Judge Brian E Murphy ruled that Health Secretary Robert F. Kennedy Jr. also likely violated federal procedures when he revamped a key vaccine advisory committee which helped secure the reforms. 

The decision handed down Monday temporarily halts Kennedy's order to end broad recommendations for all children to be vaccinated against flu, rotavirus, hepatitis A, hepatitis B, some forms of meningitis and RSV.

It also stopped a meeting of a Kennedy-appointed vaccine advisory committee, which was set to convene this week in Atlanta.

The judge's order, however, is not the final word. The blocks are temporary, pending either a trial or a decision for summary judgment.

Federal health officials indicated they planned to appeal.

'HHS looks forward to this judge's decision being overturned just like his other attempts to keep the Trump administration from governing,' said Department of Health and Human Services spokesman Andrew Nixon.

The order issued Monday is the latest development in a lawsuit filed in July 2025 by the American Academy of Pediatrics (AAP) and some other medical groups. 

The lawsuit in federal court in Boston originally focused on Kennedy's decision to stop recommending COVID-19 vaccinations for most children and pregnant women. 

The lawsuit was updated as Kennedy took more steps that alarmed medical societies, causing the plaintiffs to ask Judge Murphy to take steps to address those policy changes too.

They also asked the court to look at Kennedy's actions concerning the Advisory Committee on Immunization Practices (ACIP), which advises public health officials on what vaccines to recommend to doctors and patients.

Kennedy, a leading anti-vaccine activist before becoming the nation's top health official, fired the entire 17-member panel last year and replaced it with a group that includes several anti-vaccine voices.

Murphy, who was nominated to the bench by President Joe Biden, said Kennedy's reconstitution of ACIP likely violated federal law. He ordered the appointments and all decisions made by the reconstituted committee to be put on hold.

The ACIP was scheduled to meet this week to discuss COVID-19 vaccine safety, among other issues, but that gathering was postponed, officials said.